Having spent hundreds of nights with 2 kids all over they world (and many were not bookable as 2+2) I am fairly certain that a suite in Tokyo will serve the purpose. It worked for us at HR in the past. "fail to register guests" was not suggested by anyone on this thread so let's not go OT.
Further comments are available in Help with choosing a Hyatt in Tokyo (with toddlers)
as well as in numerous trip reports for GH and PH you can look up on the web.